Factors influencing deterioration of denitrification by oxygen entering an anoxic reactor through the surface

Benedek Gy Plósz, Andrea Jobbágy, C. P Leslie Grady

Research output: Contribution to journalArticlepeer-review

61 Citations (Scopus)

Abstract

The purpose of the paper is to examine the factors that influence the deterioration of denitrification in open anoxic reactors. For this investigation an ASM 1-based simulation model was developed and successfully applied to fit data from batch experiments carried out in lab-scale reactor vessels (uncovered and covered) using both clarified domestic wastewater and synthetic wastewater. Applying the verified model, simulation studies were performed to investigate the effects of available denitrifiable substrate, biomass concentration, oxygen transfer rate, and temperature on deterioration of denitrification in open anoxic reactors. It has been shown that oxygen entering an anoxic reactor through the surface may not just affect denitrification metabolically, but also kinetically, due to increased dissolved oxygen (DO) concentration exerting an inhibitory effect on the denitrification rate. When the exogenous substrate concentration in the reactor vessel is high enough for a high consumption rate, the DO concentration is kept low. The higher the biomass concentration, and thereby the consumption rate of endogenous substrate, the lower the DO concentration during the low-rate denitrification phase. At low substrate removal rates, decreasing temperature will cause the DO concentration in anoxic vessels to increase. The results suggest that assuring removal of available exogenous carbon source at high rate by staging of open anoxic bioreactors may significantly improve denitrification efficiency.

Original languageEnglish
Pages (from-to)853-863
Number of pages11
JournalWater Research
Volume37
Issue number4
DOIs
Publication statusPublished - Feb 2003

Keywords

  • Activated sludge
  • Denitrification
  • Modelling
  • Oxygen inhibition
  • Reactor configuration
  • Staging

ASJC Scopus subject areas

  • Earth-Surface Processes

Fingerprint Dive into the research topics of 'Factors influencing deterioration of denitrification by oxygen entering an anoxic reactor through the surface'. Together they form a unique fingerprint.

Cite this